Numbers 18:2-4

New Revised Standard Version, Anglicised Catholic Edition

² So bring with you also your brothers of the tribe of Levi, your ancestral tribe, in order that they may be joined to you, and serve you while you and your sons with you are in front of the tent of the covenant.^{[a] 3} They shall perform duties for you and for the whole tent. But they must not approach either the utensils of the sanctuary or the altar, otherwise both they and you will die. ⁴ They are attached to you in order to perform the duties of the tent of meeting, for all the service of the tent; no outsider shall approach you.